Idiopathic Pulmonary Fibrosis
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Direct answer
Insidious exertional dyspnoea, dry cough, clubbing and basal velcro crackles in an older man who smoked, with a usual interstitial pneumonia (UIP) pattern — subpleural, basal reticulation with honeycombing and traction bronchiectasis — on high-resolution computed tomography after other causes are excluded: this is idiopathic pulmonary fibrosis (IPF), a chronic progressive fibrosing interstitial pneumonia confined to the lungs. Function testing shows a restrictive defect. The antifibrotics nintedanib and pirfenidone slow the decline in lung function, and lung transplantation offers the only cure.
What you must remember
- Diagnostic anchor: a multidisciplinary diagnosis of IPF requires a UIP pattern — subpleural and basal-predominant reticulation, honeycombing with or without traction bronchiectasis, and minimal ground-glass — after excluding drug toxicity, connective tissue disease, hypersensitivity pneumonitis and asbestosis by history, serology and exposure review.
- Demography: typically above 60 years, male-predominant, past or current smokers; gastro-oesophageal reflux is a frequent association; familial clusters occur with telomere-related and MUC5B variants.
- Physiology: restriction with reduced total lung capacity and forced vital capacity, a preserved or raised FEV1/FVC ratio, reduced diffusing capacity, and exertional desaturation on the six-minute walk test; serial FVC decline (10 per cent or more) or DLCO fall marks progression.
- Antifibrotic therapy: nintedanib, an intracellular tyrosine-kinase inhibitor, and pirfenidone, an oral antifibrotic with anti-inflammatory action, each slow FVC decline by roughly half in trials; nintedanib causes diarrhoea and liver-enzyme rise (check transaminases), pirfenidone photosensitivity and gastrointestinal upset.
- Acute exacerbation: unexplained rapid deterioration with new ground-glass consolidation on a background of UIP; treated with high-dose corticosteroids per usual practice, with guarded prognosis — commonly a lethal event.
- Supportive care: oxygen for hypoxaemia, pulmonary rehabilitation, vaccination, reflux treatment, pulmonary hypertension screening and early transplant referral.
- Historical series gave a median survival of three to five years; antifibrotics and transplantation have improved the outlook, and N-acetylcysteine monotherapy showed no benefit in a large trial.
Diagnosing and managing a basal fibrosis, step by step
A 68-year-old ex-smoker has two years of breathlessness and a dry cough; examination shows clubbing and basal velcro crackles. The function tests confirm restriction — reduced total lung capacity and FVC with a preserved FEV1/FVC ratio, reduced diffusing capacity, exertional desaturation on the six-minute walk — and the high-resolution CT shows subpleural, basal-predominant reticulation with honeycombing and traction bronchiectasis and minimal ground-glass: the UIP pattern. But UIP is not synonymous with IPF, and the diagnosis is made only after the exclusions, best in multidisciplinary review: asbestosis (exposure, pleural plaques), connective tissue disease (serology, the younger woman), chronic hypersensitivity pneumonitis (bird and mould exposure, mosaic attenuation), drug toxicity. Once IPF stands, the programme is antifibrotic and supportive: nintedanib (diarrhoea, transaminase rise) or pirfenidone (photosensitivity, gastrointestinal upset), each slowing FVC decline by roughly half without reversing fibrosis; oxygen, rehabilitation, vaccination, reflux treatment, pulmonary hypertension screening and early transplant referral — the only cure. Track progression with serial FVC (a fall of 10 per cent or more) and DLCO. Warn against the two reflexes: corticosteroids, which have no established role here unlike in sarcoidosis, and N-acetylcysteine monotherapy, which showed no benefit. And counsel the family about acute exacerbation — unexplained rapid deterioration with new ground-glass consolidation on the UIP background, treated with high-dose corticosteroids per usual practice, and commonly lethal.
Where students slip
The mimic question is the reliable stem: a stepwise basal-fibrosis work-up running exposure history, serology, computed tomography pattern and multidisciplinary review, with the options planting asbestosis or hypersensitivity pneumonitis behind identical crackles. Within the idiopathic family, nonspecific interstitial pneumonia shows more ground-glass, less honeycombing and better steroid responsiveness. The steroid reflex is the commonest wrong answer, with antifibrotics the expected choice and their side-effect matching attached. The single-liners: UIP descriptors, the older male smoker with clubbing and velcro crackles, restriction with reduced diffusing capacity, the 10 per cent FVC progression marker, and acute exacerbation as the high-mortality event.
Frequently asked questions
What is the UIP pattern on high-resolution CT?
Subpleural, basal-predominant reticulation with honeycombing and traction bronchiectasis and little ground-glass — the radiological signature that defines IPF after exclusions.
What pulmonary function pattern does IPF show?
Restriction — reduced total lung capacity and FVC with a preserved ratio — plus a reduced diffusing capacity and exertional desaturation.
Which drugs slow IPF progression?
Nintedanib and pirfenidone, which about halve the rate of FVC decline; neither reverses established fibrosis.
What is an acute exacerbation of IPF?
Rapid unexplained worsening with new bilateral ground-glass change on the UIP background, treated with corticosteroids and carrying a high mortality.
Do corticosteroids help IPF?
No — steroid-based regimens have no established benefit and are the standard wrong option in exams, unlike in sarcoidosis or connective tissue interstitial disease.
What is the only curative option?
Lung transplantation for eligible candidates, making early referral part of standard care.